package com.hmdp.utils;

import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.data.redis.core.script.RedisScript;


import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @author 勋谦
 * @ClassName: SimpleRedisLock
 * @date: 2025/1/2 11:39
 * @Description:
 */
public class SimpleRedisLock implements ILock{

    private String name;
    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    @Override
    public boolean tryLook(long timeoutSec) {
        // 获取线程的标志
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        // 获取锁
        // set lock thread1 nx ex 10
        Boolean success = stringRedisTemplate.opsForValue()
                .setIfAbsent(KEY_PREFIX + name, threadId , timeoutSec, TimeUnit.MINUTES);
        // 自动拆箱可能会出现空指针异常
        return Boolean.TRUE.equals(success);
    }

    @Override
    public void unlock(){
        // 运行lua脚本 查询和判断用脚本实施，确保原子性
        stringRedisTemplate.execute(
                UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX + Thread.currentThread().getId()
        );
    }

    //@Override
    //public void unlock() {
    //    // 获取线程标识
    //    String threadId = ID_PREFIX + Thread.currentThread().getId();
    //    // 获取锁中的标识
    //    String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
    //
    //    if(threadId.equals(id)){
    //        // 释放锁
    //        stringRedisTemplate.delete(KEY_PREFIX + name);
    //    }
    //
    //}
}
